Screw holding screw driver



Aug. 22, 1950 R. H. ALEXANDER SCREW HOLDING SCREW DRIVER Filed Jan. 13,1948 l l l l l l Y y l NN. rrllllll QN MN .wN wNmN N INM .HNN NNN /sss 2IVENToR. Y H. mim/msn MFM/6mm #Mmm Patented Aug. 22, `1950 UNITED STATESPATENT OFFICE 4 Claims.

This invention relates to Screwdrivers and more particularly to ascrewdriver adapted to grip a screw so that it may be started and tothereafter release the screw so that it may be driven in the normalmaner.

A main object of the invention is to provide a novel and improvedscrewdriver of the screwgripping type which is adapted to rmly grip thescrew while it is being started, thereby eliminating the need fordrilling a hole to receive the screw prior to driving it.

A further object of the invention is to provide an improved screwdriverof the screw-gripping type wherein the screw-gripping force is increasedresponsive to pressure applied to the screwdriver handle during thescrew starting process, said screwdriver being relatively simple inconstruction, easy to manipulate and inexpensive to manufacture.

Further objects and advantages ofthe invention will become apparent fromthe following descripton and claims, and from the accompanying drawings,wherein:

Figure 1 is a longitudinal cross-sectional view taken through ascrewdriver constructed in accordance with the present invention, thescrewgripping means thereof being shown in spread position immediatelyprior to engagement with a screw.

Figure 2 is a longitudinal cross-sectional view similar to Figure 1 butshowing the screwdriver in screw-gripping position.

Figure 3 is a fragmentary cross-sectional detail view of the forwardportion of the screwdriver of Figure 1, showing the screw-gripping meansretracted to inoperative position whereby the screw driver may beemployed in the normal manner to complete the driving of the screw.

Figure 4 is a transverse cross-sectional detail view taken on line 4-4of Figure 1.

Figure 5 is a fragmentary elevational view of the forward portion of thescrewdriver of Figure 1, with the screw-gripping means shown in normalposition prior to being placed in the spread position of Figure l.

Referring to the drawings, II designates the shank of the screwdriver,said shank being formed at its forward end with a reduced bit I2 havinga blade portion I3 adapted to interlock with the driving groove of aconventional screw, such as shown at I4. Secured transversely in bit I2is a bolt member I5 formed with laterally projecting headed ends I6, I6.Surrounding the intermediate portion of shank II and longitudinallyslidable thereon is a sleeve member |165 Pivotally connected to theforward end portion of sleeve member I1 on a common transverse axis arechannel-shaped jaw members I8, I8 embracing the forward end of shank IIand formed with forwardly flaring cam surfaces I9, I9 at their forwardend portions and with inwardly tapering concave gripping seat elements20, 2i] at their forward ends. The cam elements I9, I9 arelongitudinally slotted at 2|, 2| to receive the transverse bolt memberI5, the heads I6, I6 of said bolt member bearing externally on said camelements.

Rigidly secured to the rear portion of the sleeve member I'I is anannular flange 22. Designated at 23, is a hollow handle member housingthe rear end portions of shank II and sleeve member I'I and formed witha forward sleeve portion 24 provided with an inturned annular end flange25 slidable on sleeve member Encirling the sleeve member I1 and bearingbetween iiange 25 and flange 22 is a coiled spring 26 which biases thesleeve member I1 rearwardly with respect to handle ilange 25.

The rear end portion of shank II is formed with a slot 2'I and rotatablysecured to the shank in said slot is a gear 28, the hollow handle member23 being formed with upper and lower keyways 29, 29 in the samelongitudinal plane in which said gear is located. Secured rigidly in thekeyway 29 at one side of the shank II is a first rack bar 30 meshingwith gear 28. Longitudinally slidable in the keyway 29 at the other sideof shank II is a second rack bar 3|, also meshing with gear 28. The edgeof rack bar 3| is notched at 32. Pivotally secured in a recess 33 formedin the wall of the handle member 23 adjacent rack bar 3| is a detentlever 34 biased clockwise, as viewed in Figure 1, by a spring bearingbetween the detent lever and the recess wall. One end of detent lever 34is adapted at times to interlock with the notch 32 in rack bar 3| by thebiasing action of spring 35. The other end of said lever carries arelease button 35 which projects externally of the handle member 23 forrotating said lever manually to disengage it from the notch 32.

In the normal position of the screwdriver, spring 26 acts to maintainliange 22 in abutment with the forward end of rack bar 3|. The rack bar3| is so dimensioned that under these conditions the bolt member I5 isabout midway in the cam slots 2|, 2| and the heads I6, I6 of said boltmember engage the intermediate portions of the cam elements I9, I9 andthereby hold the jaw elements I8, I8 in their partly closed positions,shown in Figure 5. To engage the head of a screw, the sleeve member I1is held and the handle member 23 is pulled rearwardly. Force is therebytransmitted to shank Il to retract said shank with respect to sleevemember I1 to the position shown in Figure 1, whereby the heads I6, I6 ofbolt member I5 travel to the rear ends of the slots 2I, 2|. In thisposition lever 34 is engaged in notch 32. This allows the jaw membersI8, I8 to be separated sufliciently to receive the head of a screw I4within the concave seat elements 20, 20 with the blade tip I3 engaged inthe kerf of the screw. Lever 34 is then released by pushing button 36and handle 23 is then moved forwardly with respect to sleeve member Il,causing shank II to be moved forwardly and moving the bolt heads I6, I6forwardly on the flaring cam surfaces I9, I9 to return the jaw membersI8, I8 to positions such as shown in Figure 2, wherein the head of screwI4 is clamped by the concave seat elements 20, 20. The screw may then bestarted and driven into its int-ended location.

vAs forward pressure is applied to handle 23 during the screw startingprocess, gear v2S `is ro.- tated counter-clockwise, as viewed in Figure2, by the forward movement of rack bar 3d. rlhis causes rack bar `3| tobe moved rearwardly. As rack bar 3I moves rearwardly out of abutmentwith flange .22, the expansive force of spring 25 is applied entirely tosaid dange and -acts on sleeve member I'I to urge said sleeve memberrearwardly with respect to shank II. 1This wedges bolt heads I6, I 6more firmly .against the forwardly daring .cam .surfaces I9, I9 andtightens the grip of the jaw members 1B, I8 on the screw head.

After the screw has been startediand it is -no vlanger necessary toclamp iit to the screwdriver bit, the screw may be released by Iholdingthe 'sleeve member Il and pulling rearwardly on the handle member 23.vThis rotates gear 28 clockwise, as viewed in Figure 2, and moves ArackbarJ3I forwardly into abutment with-flange 22, thereby exerting arearwardvpull on shank -II with respect to the sleeve member Il. Whenshank Ii moves rearwardly with respect to said sleeve member, the boltheads I I `travel rearwardly on the cam surfaces I9, kI9 andrelease thejaws I8, I8 allowing the screw head tobe disengaged from between theconcavevgripping elements '28, 20. After the screw head has-been thusdisengaged, handle member 23 is pushed forwardly with `respect to sleevemember -I`I, causing the rack bar SI to be retracted untilthe detentlever 34 enters the notch 32l in l.said rack bar. v'lChis operation alsocauses the spring 25, acting through ange 25, handleZS, rack bar Sil,and gear 28 tomove .the shank 'II forwardly with respect to sleevemember'll' until the gripping elements 2D, 2Q are inthe inoperativepositions thereof, shown -iniFigure 3, Aengaging the opposite surfacesof the blade LI3 of the screwdriver bit. Since the detent lever 34-whenseated in notch 32, opposes any furtherfor-ward movement of handlemember23 with respect to rack bar 3|, forward pressurefon the handlemember will be transmitted .directlyY to .shankf II through the rackbars 30 and 3.! and .gear 28, whereby the screwdriver may be employed-in.the driving ofthe screw. After .theioperation is completed, the pushbutton 3S is pressed inwardly, releasing the rack bar SI a-nd lallowingthe parts'to Vbe returned to their normal-positions illustrated )in`Figure 5.

While a specific embodiment of a screwdriver of the screw-gripping typehas been disclosed in the foregoing description, it will be understoodthat various modifications within the spirit of the invention may occurto those skilled in the art. Therefore, it is intended that nolimitations be placed on the invention except as defined by the scope ofthe appended claims.

What is claimed is:

l. In a screwdriver, a shank member having a bit portion adapted toengage the kerf of a Screw, a sleeve member slidable on said shankmember, a plurality of jaw elements secured to said sleeve member,inter-engaging means on said shank member and jaw elements formed andarranged to contract said jaw elements responsive to rearward axialmovement of said sleeve member with respect to said shank member, ahandle member slidable on said sleeve member, inter-engaging meanscarried by said handle vmember and shank member, a portion of saidlatter inter-engaging means being longitudinally mcvable with respect tosaid handle melilber responsive to sliding movement of the handle memberon said sleeve member and being formed and arranged to act between thesleeve member and the shank member to produce relative axial movement ofthe shank member with respect to the sleeve member in one direction, andspring means biasing the sleeve member for movement relative to theshank member in .the `opposite direction.

2. In a screwdriver, a shank member having a bit portion adapted toengage the kerf of a screw, a sleeve member slidable on said shankmember, a plurality of jaw elements pivotally secured to said sleevemember, inter-engaging cam means .on said shank member and .jawelementsformed and arrangedto contract said jaw elements responsive to rearward`axial `movementof said sleeve member with respect to said shank member,a handle member slidable on said sleeve member, a bar element slidablycarried Vvin said handle member and :bearing on said sleeve `member tooppose rearward ymovement thereof, `respective spaced .abutment,elements on said handle member and sleeve member Vlocated forwardly ofsaid bar element, a spring disposed between said abutment elements andbeing formed and arranged tobias the sleeve member rearwardly ,inopposition to said bar element, and inter-.engaging meanscarried by saidshank member and handle member and being formed and arranged to movesaid bar mem-ber out of engagement with said sleeve member responsive toforward movement v,of the handle member .on said sleeve member.

3. VIn Aa screwdriver, a shank member having abit-portion adaptedtoengage thekerf .of a screw, a sleevemember slidable Aon said shankmember, ka plurality of jaw .elements pivotally secured to said sleevemember, inter-.engaging cam means Yon saidshank member and jaw elementsformed and arranged to contractsaid jaw elements around thekerf-engaging portion ,of .the shank member responsive to rearward4axial movement of said sleeve member with respect to said shank member,a handlememberslidable onsaidsleevemember, a gear carried by said shankmember, a first rack bar rigidlycarried 'by said handle member .andmeshing with said gear, a, second rack barslidableV in. saidhandlemember and also meshing withv said gear, said-rack bars meshingwith the gear at diametrically oppositapointsron 4the gear, said second.bar

normally bearing on said sleeve member to oppose rearward movementthereof with respectI to said shank member, and a spring bearing betweenthe handle member and sleeve member in opposition to said second rackbar, said spring being formed and arranged with respect to the handlemember and sleeve member to move the sleeve member rearwardly withrespect to the shank member when said second bar is moved rearwardlywith respect to said handle member.

4. In a screwdriver, a shank member having a bit portion adapted toengage the kerk of a screw, a sleeve member slidable on said shankmember, a pair of opposed screw-head-engaging jaw elements pivotallysecured to said sleeve member, inter-engaging cam means on said shankmember and jaw elements formed and arranged to contract said jawelements around the kerf-engaging portion of the shank member responsiveto rearward axial movement of said sleeve member with respect to saidshank member, a handle member slidable on said sleeve member, a gearrotatively carried by said shank member, a first rack bar iixed to saidhandle member meshing with said gear, a second opposing rack barslidable in said handle member also meshing with said gear, said rackbars meshing with the gear at diametrically opposite points on the gear,said second rack bar normally bearing on said sleeve. member to opposerearward movement thereof with respect to said shank member, a springbearing between the handle member and sleeve member in opposition tosaid second rack bar, said spring being formed and arranged with respectto the handle member and sleeve member to move the sleeve memberrearwardly with respect to the shank member when said second bar ismoved rearwardly with respect to said handle member, and means for attimes locking said second bar in rearwardly moved position in saidhandle member.

ROY H. ALEXANDER.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 332,438 Richardson Dec. 15, 18851,399,635 Lundmark Dec. 6, 1921 FOREIGN PATENTS Number Country Date29,395 Great Britain Dec. 17, 1910

